Left-handedness without absorption in the four-level Y-type atomic medium - 赵顺才 刘正东 吴奇宣 (Chinese physics B, 2010)
Keywords: Amplification; Displays; Evanescent waves; Imaging; Joining; Lenses; Yttrium; 原子介质; 原子系统; 吸收特性; 密度矩阵方法; 成像分辨率; 相互作用; 耦合强度